The Outdoor Siren is indeed wireless and is powered by long-life Lithium-Ion batteries. This ensures that the installation of the siren is as straightforward as possible and removes the need to drill additional holes in the wall to feed power to the unit.
Batteries should last for up to twelve months but we do recommend that batteries are replaced on an annual basis.
You should note that in order to extend battery performance, the LED will only pulse blue between the hours of 7pm and 11pm. It will always pulse red, regardless of the time, when the system is activated.
The app will automatically notify you when the batteries are running low and need changing. If the batteries run out then the siren will not sound and will go offline but you will still be able to arm your system as normal.